MoSe2/WS2 heterojunction photodiode integrated with a silicon nitride waveguide for near infrared light detection with high responsivity

We demonstrate experimentally the realization and the characterization of a chip-scale integrated photodetector for the near-infrared spectral regime based on the integration of a MoSe2/WS2 heterojunction on top of a silicon nitride waveguide. This configuration achieves high responsivity of similar to 1 A W-1 at the wavelength of 780 nm (indicating an internal gain mechanism) while suppressing the dark current to the level of similar to 50 pA, much lower as compared to a reference sample of just MoSe2 without WS2. We have measured the power spectral density of the dark current to be as low as similar to 1 x 10(-12)A Hz(-0.5), from which we extract the noise equivalent power (NEP) to be similar to 1 x 10(-12) W Hz(-0.5). To demonstrate the usefulness of the device, we use it for the characterization of the transfer function of a microring resonator that is integrated on the same chip as the photodetector. The ability to integrate local photodetectors on a chip and to operate such devices with high performance at the near-infrared regime is expected to play a critical role in future integrated devices in the field of optical communications, quantum photonics, biochemical sensing, and more.

Automated summary

We successfully demonstrate a chip-scale integrated photodetector for the near-infrared spectral regime, based on a MoSe2/WS2 heterojunction integrated on a silicon nitride waveguide. The device achieves high responsivity and low dark current, making it useful for characterizing the transfer function of a microring resonator on the same chip. The integration of local photodetectors with high performance in the near-infrared regime is expected to be crucial for future integrated devices in various fields.